Reinhold



Oct. 13, 1964 G. REINHOLD 3,152,755

DEMOUNTABLE MANUAL CALCULATOR Filed Nov. 6, 1962 3 Sheets-Sheet 1 an as umn n l 1 FIG. I L. Gottwill Reinhold INVENTORI BY Jesbm, To 6 JIesiem Oct. 13, 1964 G. REINHOLD 3,152,755

DEMOUNTABLE MANUAL CALCULATOR 3 Sheets-Sheet 2 Filed Nov. 6, 1962 Oct. 13, 1964 G. REINHOLD 3,152,755

DEMOUNTABLE MANUAL CALCULATOR Filed Nov. 6, 1962 3 Sheets-Sheet :s

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GOTTWIL! REINHOL O .Mrzsfern, 72w 6 Juesiem United States Patent 3,152,755 DEMOUNTABLE MANUAL CALCULATOR Gottwill Reinhold, Bundesallee 177, Berlin-Wilmersdorf, Germany, assignor of fifty percent to Otto Kiirmer, Berlin-Wilmersdorf, Germany Filed Nov. 6, 1962, Ser. No. 235,670 14 Claims. (Cl. 235-73) My present invention relates to a manual calculator for multidigit arithmetical operations. This application is a continuation-in-part of my copending application Ser. No. 863,154 filed December 31, 1959, now abandoned.

The general object of this invention is to provide a calculator of the type referred to which is simple in construction and can be readily assembled and disassembled from prefabricated (cg. molded) parts, at low cost and with easy replacement of defective components.

A more particular object of my invention is to provide a calculator of this type which can be built up in stages, through the progressive addition of elements associated with higher-order digital positions, whereby a fully operative assembly with a relatively small number of denominational orders or decades can be expanded at will, within the physical limits of a supporting framework or housing, to encompass further denominational orders without altering the principle of its operation.

A further, related object is to provide a device of the character set forth which can be conveniently assembled from components made available in the form of a kit whereby students, mechanics and do-it yourself enthusiasts will have the opportunity of familiarizing themselves with the operation of a calculating machine.

A demountable manual calculator according to this invention, designed to satisfy the aforestated objects, comprises three principal multidigit assemblies whose digital subdivisions co-operate with one another within a given denominational order, these assemblies being an imput selector, a register or differential actuator settable by theselector and a totalizer adapted to have the selected numerical values transferred to it from the diflferential actuator. While the totalizer and the register are reinovably mounted on suitable supports rising from a base, the input selector is removably carried on the underside of a demountable cover so as to cooperate with the register when the cover engages the base. A summing mechanism, preferably including a handwheel or crank, is manually operable to displace the dilferential actuator on the base between two positions in which its several digital units alternatively contact with corresponding units of the selector and the totalizer, respectively.

The register or differential actuator, in a preferred embodiment, comprises a shaft which is both rotatable and axially shiftable by the summing mechanism and carries a plurality of substantially identical digital subassemblies each including an indexing disk with laterally and outwardly open peripheral recesses, a spine wheel having nine spines selectively cammable into these recesses under the control of the input selector, and advantageously a second spine wheel with a single spine (if only additions and/or multiplications are to be performed) or a pair of such spines (if the device is also to be used for subtractions and/or divisions) adapted to assist in the transfer of a decimal carry; any spine axially deflected toward the indexing disk co-operates with a totalizer pinion when the differential actuator is shifted to bring the totalizer assembly into play. The two types of spine wheel can be so designed that both, with such modifications (angular staggering) as may be required for successive digital positions, can be produced from identical multispine blanks through the removal of supernumerary spines, thus further facilitating mass production of the components of my improved calculator.

The above and other objects, features and advantages of this invention will become more fully apparent from the following detailed description, reference being made to the accompanying drawing in which:

FIG. 1 is a fragmentary top view of a device embodying the invention, with its housing cover and other elements removed;

. FIG. 2 is a cross-sectional view of the machine hous- FIG. 3 is a view similar to FIG. 2, showing the mechanism of the calculator within the housing;

FIG. 4 is a perspective front view of the totalizer assembly together with an associated clearing rack in disjointed position;

FIG. 5 is an exploded perspective view of part of the calculator mechanism, showing the principal elements of one denominational order;

FIG. 6 is a perspective view of a digital unit of the totalizer assembly of FIG. 4;

FIG. 7 is a front-elevational view of a pinion forming part of the unit of FIG. 6; and

FIG. 8 is a side view of the pinion shown in FIG. 7.

The calculator comprises essentially a tray-shaped base 1, preferably made of injection-molded synthetic material, from which several supports rise to receive the elements subsequently described. These supports include a pair of elongated parallel ledges 2, a pair of clip-like pedestals 4 forming bearings with retaining lugs 4a for removably receiving a shaft 5 parallel to these ledges, another pair of bearing-forming pedestals 6 adapted to receive a clearing comb 7, and several pairs of pedestals 8 forming bearings for the shafts of respective double gears 9, ha. Each of these gears is assigned to a respective digital order of the calculator and co-operates with an associated rack 11 slidable between guides 10 on base 1; the racks 11 mesh with the teeth 9a of the respective double gears. The pedestals 8 rise from a trough 12 on base 1 accommodating the lower parts of gears 9; a similar trough 13 in line with pedestal 4 accommodates the elements of a multidigit register or differential actuator of which the shaft 5 forms a part.

A multidigit totalizer assembly, designed to co-operate with the aforementioned actuator, comprises a frame 3 whose lower ledge 3a is movably received between the ledges 2. This frame has a horizontal channel.34 accommodating a clearing rack 31 which is slidable therein for resetting the elements of the totalizer, the rack 31 being for this purpose provided with a handle 32 which passes upwardly through a slot 63 in a cover 16. The cover, which also has an L-shaped cutout 60 for the rack 31, is removably retained on the base 1 with the aid of clips 14-, 15 which engage in suitable recesses in the cover as best seen for the clip 15 in FIG. 2. The totalizer assembly can be manually shifted in a transverse horizontal direction (up and down in FIG. 1) by a stud 33 rising from frame 3 and passing through slot 64 in rack 31.

The totalizer frame 3 carries a set of dials 23 which are viewable through a window 65 in cover 16 and register the several digits of the calculated result. Each of these dials forms part of a respective digital order of the totalizer. The frame 3 carries pairs of clips 30a, similar to the clips 4, to receive the stub shafts 50 of respective pinions 26; there is one such pinion provided for each digital order, its teeth meshing with a crown gear 22 rigidly coupled with the associated dial 23 by means of a shaft 24 traversing a hole 25 in the frame. Similar pairs of clips 30, numbering one less than the pairs of clips 30a, accommodate the studs 29 of respective transfer levers 3 28 each having one of its arms passing through a clearance in frame 3 for engagement with a flat spring 61 (FIG. 1). The other arm of lever 28 has a projection 44 (FIG. 6) engageable by a cam 43 which is rigid with pinion 26 on shaft 50; the end of this latter arm also has a beveled extremity 46 and a projection 47.

The multidigit diiferential actuator or register comprises a plurality of digital units spaced on shaft each of these units is positioned for co-operation with a respective pinion 26 of the totalizer and a respective rack 11 of the input mechanism. A spring 52, anchored to the base 1 through the intermediary of one of the pedestals 4 and to the shaft 5 via a start-stop wheel 35 thereon, tends to maintain this shaft with its register assembly in an axial position in which the racks 11 mesh with gear teeth 27b on respective cam disks 27 bearing camming segments 37. Each digital unit of the differential actuator includes an indexing disk 36 provided with peripheral recesses 36a and 360, a spine wheel 18 keyed to the hub 36b of disk 36 on the side of its recesses 36a, another spine wheel 17 keyed to the same hub on the side of the recesses 36c, and the aforementioned cam disk 27 whose hub 27a, likewise carried on hub 36b beyond wheel 18, enables free rotation of disk 27 with its segments 37 and its teeth 27 b relative to the remainder of the unit.

The cover 16 further accommodates a multidigit selector comprising a series of numerical bars 39 carrying rack teeth 40. The bars 39 are slidably received in channels 38 underneath the cover which has suitable openings to give access to the numbered compartments of these bars. The latter are thus downwardly slidable, with their rack teeth 40 engaging the gear teeth 9, whereby the corresponding rack 11 driven by gear teeth 9a moves in opposite direction as indicated by the arrows in FIG. 5. Flanges 38a serve as lateral guides for the rack teeth 40 and releasably hold the selector bars on the covers. The racks 11 also have shoulders 11a engageable by the depending teeth 7b of clearing comb 7 when the handle portion 7a thereof is swung clockwise (arrow in FIG. 3) to restore both racks 11 and 39 to a starting position in which the racks 11 abut a stop 66 on base 1.

The start-stop disk 35 has a notch 35a normally occupied by a detent 42 rising from base 1. When the shaft 5 is pulled axially to the right (as viewedin FIG. 5) by a crank 62 engaging its flat extremity 5a, disk 35 is disengaged from detent 42 so as to be freely rotatable through an angle of 360 in either direction for an additive or subtractive summing operation.

The wheel 18 has nine spines 19 which are receivable in respective recesses 36a of disk 36 and project radially therebeyond as clearly seen in FIG. 3. Wheel 17 has two similar spines 17a, 17b which are angularly offset from the spines 19, as likewise best seen in FIG. 3, and receivable in respective recesses 36c of the disk. FIG. 3 also shows how the spines 17a, 17b and 17a, 17b of successive digital orders are angularly staggered relatively to one another while being symmetrically positioned between the location of the spines 19 and a diametrically opposite location occupied by two blocks 20, 21 adapted to cooperate with the projection 47 of an associated transfer lever 28. The entire circumference of disk 36 is divided into thirty sectors of which three are occupied by the blocks and 21, nine of the remaining twenty-seven sectors being reserved for the spines 19 whereas the other eighteen sectors represent the positions of respective pairs of spines 17a, 17b to 17a, 17b. To insure proper alignment between the spines of wheels 17, 18 and their associated recesses 36a, 3360, cam disk 27 is provided with a resilient indexing tab 41 adapted yieldably to snap into any recess 36a registering therewith.

The spine wheels 17, 18 are advantageously formed from identical blanks having twenty-seven spines in the sectoral positions referred to above. Eighteen of these spines are removed when it is desired to produce a wheel 18, whereas only two are left in place for the obtention 4.- of one of the wheels 17. The spines allowed to remain, being integral with the wheel hub, are resiliently defiectable in the direction of the wheel axis.

In operation, the selection of a multidigit addend or subtrahend by manual operation of respective selector bars 39, with the shaft 5 and its differential actuator assembly in the normal position shown in FIG. 1, cause the cam disks 27 of the corresponding digital orders to be rotated through a number of tooth divisions of gear 2711 determined by the extent of the displacement of the bars. Thus, as a result of such displacement, the segment 37 of each disk 27 so rotated cams one or more spines 19 of the associated wheel 18, which can be axially deflected by virtue of their inherent resiliency, into the recesses 36a of disk 36 assigned to them. The tips of these deflected spines 19 project beyond the periphery of disk 36 so as to be alignable with the teeth of the pinion 26 of the corresponding digital order upon an axial shifting of the shaft 5, by means of crank 62, against the force of compression spring 52 whereby the gear teeth 27b are simultaneously disengaged from the respective racks 11.

The operator next rotates the shaft 5 with the aid of crank 62 in one or the other direction, depending on whether addition or subtraction is desired. This causes entrainment of some or all of the digit pinions 26 of the totalizer by the tips of the deflected spines 19 in their disk recesses 36a. The rotation of each pinion 26 is communicated to the associated totalizer dial 23 via crown gear 22 and shaft 24.

Whenever a pinion 26 completes a full revolution so that the cam 43 rigid therewith passes through a predetermined angular position, this cam sets the adjoining transfer lever 28 by swinging it counterclockwise (as viewed in FIG. 3) into an alternate position in which it is yieldably held by the spring 61 while its beveled end 46 extends into the path of the tips of spines 17a, 17b of the wheel 17 belonging to the next-higher digital order. When, during rotation of the shaft 5, the first of these spines passes the preset lever 28, its extremity 46 cams this spine into the assigned recess 360 of the indexing disk 36 of the next order at precisely the instant when the tip of the spine approaches the teeth of the pinion 26 of that order (see FIG. 6). This pinion 26' is thereby rotated about its shaft 50 and advanced by one tooth to change the indication of the corresponding dial 23 by the addition or subtraction of a value of unity. Since the spines 17a, 17b of successive wheels 17 are angularly staggered as shown in FIG. 3, a tens carry may be added or subtracted in this manner in successive denominational orders in the course of a single summing operation. After the spine 17a or 17b has stepped the pinion 26' by one tooth, the movement of block 20 or 21 past projection 47 cams the lever 28 back into its normal position, shown in FIG. 3, in which it is again yieldably retained by spring 61. Naturally, no such transfer mechanism need be provided for the highest-order digital stage of the totalizer.

When shaft 5 has been turned through a complete revolution, the operator releases the crank 62 to enable the detent 42 to re-engage in the notch 35a in start-stop wheel 35 as the gear teeth 27b of cam disks 27 are returned by spring 52 into registry with the respective racks 11 preparatorily to the next selecting and summing cycle.

The input selector and the selector bars 39 thereof can be cleared with the aid of comb 7 after the shaft 5 has been restored to normal axial position, this same clearing action returning the carnming segments 37 to their starting positions since gears 27b and racks 11 will resume their original relationship after each complete turn of the crank 62. As the totalizer dials 23 are then no longer coupled with the register or differential actuator on shaft 5, they too may be restored to normal by the reciprocation of clearing rack 31 whose teeth are normally out of mesh with co-operating teeth 23a on dials 23; as each dial reaches its zero position, a gap between its teeth 23a confronts the rack 31 so that further shifting of the latter Within the limits of groove 64 remains without effect on its angular position.

My improved manual calculator may be used for all four fundamental arithmetical operations (addition, subtraction, multiplication and division) in the same manner as other such devices provided with a shiftable totalizer, e.g. the calculator disclosed in my copending application Ser. No. 190,760 filed April 27, 1962 (continuation-inpart of Ser. No. 657,519 filed May 7, 1957). Thus, the first number registered on the selector bars 39 and transferred into the totalizer 23 may serve as an augend, minuend, multiplicand or dividend according to the subsequent operations to be performed, the number so registered remaining unchanged on the selector bars in the case of multiplication and division being replaced by an addend, or subtrahend in the two other cases. As will be apparent from FIG. 1, extra digital positions are provided on the totalizer as compared with the input selector, there being present nine holes 25 for a like number of dials 23 but only enough guides to accommodate seven racks 11. With the transfer lever 28 omitted in each of the three highest-order digital positions of the totalizer, which therefore become inoperative insofar as registration of a total or a dividend is concerned, the system illustrated in the drawing may be used to perform multiplications with totals having a maximum of six digits and divisions with dividends of six digits or less and quotients of not more than three digits; for this purpose the extreme left-hand bar 39 (top digital position in FIG. 1) is set to the value 1 for multiplications and 9 for divisions whereby the left-hand portion of the totalizer acts as a revolutions counter to register the number of iterative additions (multiplier) or subtractions (quotient). Iterative additions require a shift of the totalizer frame 3 from left to right or vice versa between successive digits of the multiplier; with iterative subtractions the totalizer displaying the multidigit dividend is first moved to the right (down in FIG. 1) and then displaced from right to left whenever the divisor stored in the input register 39 exceeds the value registered in corresponding digital positions of the totalizer, the last such value being the remainder.

The device shown and described admits, of course, of numerous modifications (e.g. changes in the number of selector, register and/ or totalizer stages) without departing from the spirit and scope of the invention as defined in the appended claims.

I claim:

1. A manual calculator comprising a base, first and second supporting means on said base; a multidigit totalizer assembly removably mounted on said first supporting means; a multidigit differential actuator removably mounted on said second supporting means adjacent said totalizer assembly; a cover removably engageable with said base; a multidigit numerical selector removably,

mounted on said cover for operative engagement with said differential actuator; manually operable summing means carried by said differential actuator for displacing the latter on said second supporting means into operative engagement with said totalizer assembly and transferring thereto a set of digits previously introduced into said differential actuator by said selector, said differential actuator comprising a shaft, said second supporting means forming bearings for said shaft, said summing means comprising crank means on an extremity of said shaft for rotating same, said shaft being axially displaceable in said bearings by said crank means into a position of engagement of said diiferential actuator with said totalizer assembly, said base being composed of a synthetic resin, said first and second supporting means including resiliently spreadable clips of said synthetic resin releasably retaining said assembly and said differential actuator, and spring means anchored to said base and to said shaft for restoring said differential actuator to a normal position disengaged from said totalizer assembly.

2. A manual calculator comprising a base; a multidigit totalizer assembly removably mountedon said base; a multidigit differential actuator removably mounted on said base adjacent said totalizer assembly; a cover engageable with said base; a multidigit numerical selector mounted on said cover for operative engagement with said differential actuator; manually operable summing means carried by said differential actuator for displacing the latter on said base into operative engagement with said totalizer assembly and transferring thereto a set of digits previously introduced into said difierential actuator by said selector, said differential actuator comprising a shaft, said base forming bearings for said shaft, said summing means comprising crank means on an extremity of said shaft for rotating same to transfer digits from said actuator to said assembly, said shaft being axially displaceable in said bearings by said crank means into a position of engagement of said differential actuator with said totalizer assembly; and spring means anchored to said base and to said shaft for restoring said differential actuator to a normal position disengaged from said totalizer assembly, said shaft being operatively engageable alternatively with said selector and said totalizer assembly in respective axial positions of said shaft; said differential actuator comprises a plurality of digital units axially spaced on said shaft for co-operation with respective elements of said selector and of said totalizer assembly forming part of corresponding digital orders; each of said units including an indexing disk keyed to said shaft and provided with at least one set of peripherally spaced laterally and outwardly open recesses, a spine wheel adjacent said disk having nine axially flexible spines respectively aligned with certain of said recesses and resiliently receivable therein while projecting radially outwardly thereoeyond, and cam means adjacent said spine wheel rotatable relatively thereto by the associated selector element for axial displacement of a variable number of said spines into said recesses; each digital order of said totalizer assembly including a pinion engageable by the tips of said spines in their axially displaced positions and a numerical indicator coupled with said pinion and viewable through said cover for registering the number of spines so displaced.

3. A calculator according to claim 2 wherein each digital order'of said totalizer assembly except the last one further comprises a transfer cam presettable by said pinion in a predetermined angular position thereof for transmitting a tens carry to the next-higher digital order, each of said units except the last one further including a second spine wheel positioned adjacent the indexing disk of the unit corresponding to the next-higher digital order and provided with at least one axially flexible spine resiliently displaceable into a recess of the last-mentioned disk by the preset transfer cam for advancing the pinion of said next-higher digital order by one step.

4. A calculator according to claim 3 wherein the spines of said second spine wheels of successive units are progressively angularly staggered.

5. A calculator according to claim 3 wherein said totalizer assembly comprises an upright frame provided with pairs of clips, said pinions and said transfer cams each having a shaft removably held by a respective one of said pairs of clips, said first base comprising a pair of upstanding ridges receiving a lower edge portion of said frame between them.

6. A calculator according to claim 5, further comprising resetting means for said indicators shiftable on said frame and accessible through said cover.

7. A calculator according to claim 3 wherein each of said spine wheels has a hub integral with the spines thereof, the spines and the hubs of all said spine wheels being of like configuration and derivable from identical multispine blanks by the removal of redundant spines from the hubs thereof.

8. A calculator according to claim 3, further comprising a projection on said disk for returning a preset transfer cam to an inoperative position in a predetermined angular position of said disk.

9. A calculator according to claim 2 wherein associated elements of said selector, said differential actuator and said totalizer assembly forming part of the same digital order are molded from plastic material of a common color distinguishing them from elements of a different digital order.

10. A calculator according to claim 2 wherein said selector includes a numerical bar for each digital order, said bar being slidably held in said cover and accessible from above for manual displacement, further comprising supporting means on said base, first gear means individual to each bar removably journaled on said supporting means, a first rack on each bar mating with said first gear means, guide means on said base, a second rack individual to each bar removably engaged by said guide means and mating with said first gear means, and second gear means individual to each bar rigid with said cam means of a respective digital unit and mounted on said shaft for engagement with said second rack in said normal position.

11. A calculator according to claim 10, further comprising other supporting means on said base and a clearing member removably positioned on said other supporting means, said clearing member being accessible through said cover and engageable with said second racks for returning them to a starting position.

12. A manual calculator comprising a base; a multidigit totalizer assembly removably mounted on said base; a multidigit differential actuator removably mounted on said base adjacent said totalizer assembly; a cover engageable with said base; a multidigit numerical selector mounted on said cover for operative engagement with said differential actuator; manually operable summing means carried by said differential actuator for displacing the latter on said base into operative engagement with said totalizer assembly and transferring thereto a set of digits previously introduced into said differential actuator by said selector, said differential actuator comprising a shaft, said base forming bearings for said shaft, said summing means comprising crank means on an extremity of said shaft for rotating same to transfer digits from said actuator to said assembly, said shaft being axially displaceable in said bearings by said crank means into a position of engagement of said differential actuator with said totalizer assembly; said spring means anchored to said base and to said shaft for restoring said differential actuator to a normal position disengaged from said totalizer assembly, said shaft being operatively engageable alternatively with said selector and said totalizer assembly in respective axial positions of said shaft, said calculator further comprising a start-stop disk on said shaft provided with a peripheral notch, and a detent on said base normally engaging said notch but adapted to maintain said shaft axially displaced against the force of said spring means upon rotation beyond a starting position.

13. A manual calculator comprising support, a multidigit numerical selector on said support, a multidigit totalizer assembly on said support, and a multidigit differential actuator positioned on said support for alternate cooperation with said selector and said totalizer assembly; said differential actuator including a rotatable and axially shiftable shaft, a plurality of digital units axiaiiy spaced on said shaft for co-operation with respective elements of said selector and of said totalizer assembly forming part of corresponding digital orders, each of said units including an indexing disk keyed to said shaft and provided with at least one set of peripherally spaced laterally and outwardly open recesses, a spine wheel adjacent said disk having nine axially flexible spines respectively aligned with certain of said recesses and resiliently receivable therein while projecting radially outwardly therebeyond, and cam means adjacent said spine wheel rotatable relatively thereto by the associated selector element for axial displacement of a variable number of said spines into said recesses, each digital order of said totalizer assembly including a pinion engageable by the tips of said spines in their axially displaced posi tions and a numerical indicator coupled with said pinion for registering the number of spines so displaced upon rotation of said shaft.

14. A calculator according to claim 13 wherein each digital order of said totalizer assembly except the last one further comprises a transfer cam presettable by said pinion in a predetermined angular position thereof for transmitting a tens carry to the next-higher digital order, each of said units except the last one further including a second spine wheel positioned adjacent the indexing disk of the unit corresponding to the next higher digital order and provided with at least one axially flexible spine resiliently displaceable into a recess of the last-mentioned disk by the preset transfer cam for advancing the pinion of said next-higher digital order by one step, the spines of said second spine wheels of successive units being progressively angularly staggered.

References Cited in the file of this patent UNITED STATES PATENTS 121,687 Teasdale Dec. 5, 1871 706,180 Hultman Aug. 5, 1902 847,759 Gaucher et a1 Mar. 19, 1907 979,358 Trinks Dec. 20, 1910 1,035,066 Witsell Aug. 6, 1912 1,104,763 Augustin July 28, 1914 1,474,137 Beckenbauer Nov. 13, 1923 2,528,149 Kraft Oct. 31, 1950 2,726,482 Roehrl Dec. 13, 1955 2,744,686 Gnip May 8, 1956 2,879,938 Menge Mar. 31, 1959 

1. A MANUAL CALCULATOR COMPRISING A BASE, FIRST AND SECOND SUPPORTING MEANS ON SAID BASE; A MULTIDIGIT TOTALIZER ASSEMBLY REMOVABLY MOUNTED ON SAID FIRST SUPPORTING MEANS; A MULTIDIGIT DIFFERENTIAL ACTUATOR REMOVABLY MOUNTED ON SAID SECOND SUPPORTING MEANS ADJACENT SAID TOTALIZER ASSEMBLY; A COVER REMOVABLY ENGAGEABLE WITH SAID BASE; A MULTIDIGIT NUMERICAL SELECTOR REMOVABLY MOUNTED ON SAID COVER FOR OPERATIVE ENGAGEMENT WITH SAID DIFFERENTIAL ACTUATOR; MANUALLY OPERABLE SUMMING MEANS CARRIED BY SAID DIFFERENTIAL ACTUATOR FOR DISPLACING THE LATTER ON SAID SECOND SUPPORTING MEANS INTO OPERATIVE ENGAGEMENT WITH SAID TOTALIZER ASSEMBLY AND TRANSFERRING THERETO A SET OF DIGITS PREVIOUSLY INTRODUCED INTO SAID DIFFERENTIAL ACTUATOR BY SAID SELECTOR, SAID DIFFERENTIAL ACTUATOR COMPRISING A SHAFT, SAID SECOND SUPPORTING MEANS FORMING BEARINGS FOR SAID SHAFT, SAID SUMMING MEANS COMPRISING CRANK MEANS ON AN EXTREMITY OF SAID SHAFT FOR ROTATING SAME, SAID SHAFT BEING AXIALLY DISPLACEABLE IN SAID BEARINGS BY SAID CRANK MEANS INTO A POSITION OF ENGAGEMENT OF SAID DIFFERENTIAL ACTUATOR WITH SAID TOTALIZER ASSEMBLY, SAID BASE BEING COMPOSED OF A SYNTHETIC RESIN, SAID FIRST AND SECOND SUPPORTING MEANS INCLUDING RESILIENTLY SPREADABLE CLIPS OF SAID SYNTHETIC RESIN RELEASABLY RETAINING SAID ASSEMBLY AND SAID DIFFERENTIAL ACTUATOR, AND SPRING MEANS ANCHORED TO SAID BASE AND TO SAID SHAFT FOR RESTORING SAID DIFFERENTIAL ACTUATOR TO A NORMAL POSITION DISENGAGED FROM SAID TOTALIZER ASSEMBLY. 